rechargeable aqueous zinc-ion batteries in mgso4/znso4
TRANSCRIPT
Nano-Micro Letters
S1/S9
Supporting Information for
Rechargeable Aqueous Zinc-Ion Batteries in MgSO4/ZnSO4 Hybrid
Electrolytes
Yingmeng Zhang1, 2, 3, Henan Li4, *, Shaozhuan Huang5, Shuang Fan5, Lingna Sun1, Bingbing
Tian2, Fuming Chen6, Ye Wang7, Yumeng Shi2, 3, *, Huiying Yang5, *
1College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen,
Guangdong 518060, People’s Republic of China
2International Collaborative Laboratory of 2D Materials for Optoelectronics Science and
Technology of Ministry of Education, Institute of Microscale Optoelectronics, Shenzhen
University, Shenzhen 518060, People’s Republic of China
3Engineering Technology Research Center for 2D Material Information Function Devices and
Systems of Guangdong Province
4College of Electronic Science and Technology, Shenzhen University, Shenzhen 518060,
People’s Republic of China
5Pillar of Engineering Product Development, Singapore University of Technology and Design,
8 Somapah Road, 487372, Singapore
6School of Physics and Telecommunication Engineering, South China Normal University,
Guangzhou 510006, People’s Republic of China
7Key Laboratory of Material Physics of Ministry of Education, School of Physics and
Engineering, Zhengzhou University, Zhengzhou 450052, People’s Republic of China
*Corresponding authors. E-mail: [email protected] (Huiying Yang),
[email protected] (Yumeng Shi), [email protected] (Henan Li)
S1 Supplementary Note
S1.1 Estimation of the Capacitive Contribution and Diffusion-controlled Contribution
Figure 4g in the main text displays two reduction peaks and two oxidation peaks in each CV
curve.
Generally, the measured peak currents (i) and scan rates (v) have a relationship follows the
power law as below:
i = avb
which can be rewritten as,
log(i) = log(a) + b·log(v)
Therefore, the b value can be acquired by fitting slope of the log(i) versus log(v) profile. The
b value is often in a range of 0.5–1.0, where a b value tends to 0.5 indicates the
electrochemical process is controlled by ionic diffusion, while the b value reaches to 1.0
corresponds to the capacitive dominated behavior.
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Assuming the current response (i) depends on a combination of the pseudocapacitance and
diffusion-controlled process, the capacitive contribution can be further quantitatively
calculated according to the following equation:
i = k1v + k2v1/2
which can be reformulated as,
i/v1/2 = k1v1/2 + k2
where k1v and k2v1/2 represent the capacitive and ionic diffusion contribution, respectively.
The capacitive contribution can be estimated by determining the k1 value, which can be
obtained by fitting the i/v1/2 vs. v1/2 plots.
S1.2 Estimation of the Diffusion Coefficient Values Calculated for the MgVO Cathodes
in the Five Different Electrolytes
The diagonal lines in the low-frequency region presented in the EIS results are assigned to the
ion diffusion in the electrode materials. The diffusion coefficient values can be quantitatively
calculated by Eqs. S1 and S2:
2/1−++= LD RRZ (S1)
22442
22
n2 CFA
TRD = (S2)
In Eq. S1, Z' is defined to be the Warburg impedance, ω is the angular frequency in the low
frequency region, RD is the diffusion resistance, and RL is the liquid resistance. And the
Warburg impedance coefficient (denoted by σ) is the key factor what we want to obtain,
which is calculated by the slope of the oblique line corresponding to the relationships between
Z' and ω-1/2 in the low frequency region. In the Eq. S2, D denotes diffusion coefficient, R is
the gas constant, T is denoted as the thermodynamic temperature, A is the effective contract
area of the electrode, F is the Faraday constant, and C is the concentration of the active ions.
S2 Supplementary Figures and Tables
10 20 30 40 50 60 70
Inte
nsi
ty (
a.
u.)
2 (degrees)
PCPDS#720433
V2O
5
Fig. S1 The XRD pattern of the commercial V2O5 reagent
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a b
1308 1306 1304 1302 1300
1304.2 eV
Inte
nsi
ty (
a.u
.)
Binding Energy (eV)
Mg 1s
535 530 525 520 515 510
O 1s
Inte
nsi
ty (
a.u
.)
Binding Energy (eV)
V 2p
524.6eV
V 2p2/1
517.3eV
V 2p3/2
Fig. S2 The XPS spectra of the MgVO material
0.2 0.4 0.6 0.8 1.0 1.2 1.4
-500
0
500
1000
1500
A
D
C
B 2M ZnSO4
1.5M ZnSO4+0.5M MgSO4
1.0M ZnSO4+1.0M MgSO4
d
Q/d
V(m
Ah
g-1/V
)
Potential/V vs. Zn/Zn2+
Fig. S3 The corresponding derivative dQ/dV response derived from the discharge–charge
profiles of MgVO cathode at current density of 100 mA g−1 in different electrolytes
a
b
c
d
e
Fig. S4 Voltage profiles as a function of time for zinc plating/stripping experiments in
symmetric Zn/electrolyte/Zn cells cycled at a current density of 10 mA/cm2 for 5000 cycles,
the electrolytes are (a) 2.0 M ZnSO4, (b) 1.5 M ZnSO4–0.5 M MgSO4, (c) 1.0 M ZnSO4–1.0
M MgSO4, (d) 0.5 M ZnSO4–1.5 M MgSO4, and (e) 2.0 M MgSO4 electrolytes
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0 500 1000 1500 2000 25000
50
100
150
200
250
2M ZnSO4
1.5M ZnSO4+0.5M MgSO4
1.0M ZnSO4+1.0M MgSO4
0.5M ZnSO4+1.5M MgSO4
2M MgSO4
Sp
ecif
ic c
ap
aci
ty (
mA
h g
-1)
5000 mA/g
Cycle number
Fig. S5 Prolonged cycling performance of the MgVO cathodes in five different electrolytes of
2Zn0Mg, hybrid 1.5Zn0.5Mg, hybrid 1.0Zn1.0Mg, hybrid 0.5Zn1.5Mg and 0Zn2Mg,
respectively, with the current density of 5000 mA g−1
After 2500 cycles at a current density of 5000 mA g−1, it can be observed that a relatively
good cycling stability of the MgVO cathode is measured in the 2Zn0Mg, 1.5Zn0.5Mg and
1.0Zn1.0Mg electrolytes, while the testing in the 0.5Zn1.5Mg and 0Zn2Mg electrolytes shows
an obvious capacity fading. Among them, the electrode in the 1.0Zn1.0Mg electrolyte exhibits
the slowest capacity fading.
a b
0 100 200 300 400 5000
50
100
150
200 2M ZnSO4
1.5M ZnSO4+0.5M MgSO4
1.0M ZnSO4+1.0M MgSO4
0.5M ZnSO4+1.5M MgSO4
2M MgSO4
Sp
ecif
ic c
ap
aci
ty (
mA
h g
-1)
1000 mA/g
Cycle number0 200 400 600 800 1000
0
50
100
150
200 2M ZnSO4
1.5M ZnSO4+0.5M MgSO4
1.0M ZnSO4+1.0M MgSO4
0.5M ZnSO4+1.5M MgSO4
2M MgSO4
Sp
ecif
ic c
ap
aci
ty (
mA
h g
-1)
2000 mA/g
Cycle number
Fig. S6 Cycling performance of the commercial V2O5 powder cathodes in five different
electrolytes of 2Zn0Mg, hybrid 1.5Zn0.5Mg, hybrid 1.0Zn1.0Mg, hybrid 0.5Zn1.5Mg and
0Zn2Mg, respectively, with the current density of 1000 mA g−1 (a) and 2000 mA g−1 (b)
As shown in Fig. S6, it can be observed that the specific capacities increase over several
hundred cycles until to a maximum value except for the cathode in the 2.0 M MgSO4
electrolyte, indicating that a gradual activation is highly required to improve the kinetics and
the discharge capacity can then be fully displayed. The cathodes in the hybrid 1.5Zn0.5Mg
and hybrid 1.0Zn1.0Mg electrolytes show a stable cycling performance after the electrode
activation. By contrast, the cathode in the 2.0 M ZnSO4 electrolyte presents the gradually
decreased capacities.
Nano-Micro Letters
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a b
Zw
RsRct
CPE
W
0 100 200 300 4000
50
100
150
200
250
300 2M ZnSO4
1.5M ZnSO4+0.5M MgSO4
1.0M ZnSO4+1.0M MgSO4
0.5M ZnSO4+1.5M MgSO4
2M MgSO4
-Z''
(O
hm
)
Z' (Ohm)1.0 1.5 2.0 2.5 3.0 3.5 4.0
0
200
400
600
800
1000
1200
2M ZnSO4
1.5M ZnSO4+0.5M MgSO4
1.0M ZnSO4+1.0M MgSO4
0.5M ZnSO4+1.5M MgSO4
2M MgSO4
Z'
(Oh
m)
-1/2
Fig. S7 (a) Nyquist plots of the MgVO electrodes in five different electrolytes, which were
carried out in the frequency range of 0.01−100kHz. The inset shows the corresponding
equivalent EIS circuitry model. (b) The line relationship of the cathodes in five electrolytes
between Z' and ω-1/2 in the frequency region of 0.1-0.01 Hz
a c
b d
Image
2 nm
e
f0.206 nm
Fig. S8 Characterization of the MgVO cathode at the fully second discharged state when
cycling at current density of 100 mA g−1 in the 1.0 M ZnSO4–1.0 M MgSO4 electrolyte: (a-d)
SEM-EDS elemental mapping images, (e) TEM image, (f) the corresponding HRTEM image
a c
b d
Image
2 nm
e
f
0.210 nm
Fig. S9 Characterization of the MgVO cathode at the fully second charged state when cycling
at current density of 100 mA g−1 in the 1.0 M ZnSO4–1.0 M MgSO4 electrolyte: (a-d) SEM-
EDS elemental mapping images, (e) TEM image, (f) the corresponding HRTEM image
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b
10 20 30 40 50 60 70
Inte
nsi
ty (
a.
u.)
2 (degrees)
Ca
rb
on
pa
per
Ca
rb
on
pa
per
PDF#50-0570 Zn3(OH)
2V
2O
7•2H
2Oa
10 20 30 40 50 60 70
Inte
nsi
ty (
a. u
.)
2 (degrees)
21
100
8
11
5
Ca
rbo
n p
ap
er
00
3
00
2
00
1
Ca
rbo
n p
ap
er*
*
*
*
Fig. S10 XRD patterns of the MgVO cathode at the fully second discharged (a) and charged
(b) state when cycling at current density of 100 mA g−1 in the 1.0 M ZnSO4–1.0 M MgSO4
electrolyte
a b
c d
e f
525 520 515
fully discharged
523.8eV
V4+
2p2/1
516.3eV
V4+
2p3/2
Inte
nsi
ty (
a.u
.)
Binding Energy (eV)
V 2p
525.0eV
V5+
2p2/1
517.4eV
V5+
2p3/2
1050 1040 1030 1020
pristine
Inte
nsi
ty (
a.u
.)
Binding Energy (eV)
Zn 2p
1050 1040 1030 1020
fully charged
Inte
nsi
ty (
a.u
.)
Binding Energy (eV)
Zn 2p
1044.9eV
Zn 2p2/1
1021.8eV
Zn 2p3/2
1050 1040 1030 1020
1044.9eV
Zn 2p2/1
1021.8eV
Zn 2p3/2
fully discharged
intercalated
Zn 2p2/1
intercalated
Zn 2p3/2
Inte
nsi
ty (
a.u
.)
Binding Energy (eV)
Zn 2p
525 520 515
fully charged
523.8eV
V4+
2p2/1
516.3eV
V4+
2p3/2
Inte
nsi
ty (
a.u
.)
Binding Energy (eV)
V 2p
524.6eV
V5+
2p2/1
517.3eV
V5+
2p3/2
525 520 515
pristine
Inte
nsi
ty (
a.u
.)
Binding Energy (eV)
V 2p
524.4eV
V5+
2p2/1
517.3eV
V5+
2p3/2
Fig. S11 XPS spectra of the MgVO cathode cycled at current density of 100 mA g−1 in the 1.0
M ZnSO4–1.0 M MgSO4 electrolyte: Zn 2p region of the XPS spectra (a, c, e), and V 2p
region of the XPS spectra (b, d, f). Pristine material (a, b), the fully discharged electrode (c,
d) and the fully charged electrode (e, f)
Nano-Micro Letters
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a b
c d
e f
1308 1306 1304 1302 1300
1304.2 eV
Inte
nsi
ty (
a.u
.)
Binding Energy (eV)
Mg 1s
1050 1040 1030 1020
1044.9eV
Zn 2p2/1
1021.8eV
Zn 2p3/2
intercalated
Zn 2p2/1 intercalated
Zn 2p3/2
Inte
nsi
ty (
a.u
.)
Binding Energy (eV)
Zn 2p
525 520 515 510
523.0eV
V4+
2p2/1
516.0eV
V4+
2p3/2
Inte
nsi
ty (
a.u
.)
Binding Energy (eV)
V 2p
524.7eV
V5+
2p2/1
517.3eV
V5+
2p3/2
500 nm 100 nm
10 20 30 40 50 60 70
Inte
nsi
ty (
a.
u.)
2 (degrees)
Ca
rbo
n p
ap
er
Ca
rbo
n p
ap
er
PDF#50-0570 Zn3(OH)
2V
2O
7•2H
2O
Fig. S12 (a) XRD pattern, (b-d) XPS spectra, (e) SEM image and (f) TEM image of the
MgVO cathode at the 100th cycle charged state when cycling at the current density of 1 A g−1
for 100 cycles in the 1.0 M ZnSO4–1.0 M MgSO4 electrolyte
2Zn0Mg1.5Zn0.5Mg1.0Zn1.0Mg0.5Zn1.5Mg0Zn2Mg
Fig. S13 Optical image of the MgVO electrodes in different electrolytes for 24 h. With the
increase of MgSO4 concentration, the dissolution of active material is effectively controlled
Nano-Micro Letters
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a b cImage
dImage
fe
Fig. S14 SEM-EDS elemental mapping images of the Zn anodes at the fully discharged (a-c)
and charged (d-f) states when cycling at current density of 100 mA g−1 in the 1.0 M ZnSO4–
1.0 M MgSO4 electrolyte
Table S1 Comparison of electrochemical properties of MgVO with previously reported metal
vanadate cathode materials for aqueous ZIBs
Metal vanadates Electrolytes Rate performance Cycling performance References
MgxV2O5·nH2O
1.0 M
ZnSO4–1.0
M MgSO4
374, 330, 280, 241,
216, and 175 mA h
g−1 at 0.1, 0.2, 0.5, 1,
2, and 5 A g−1,
respectively
90% after 200 cycles at 1 A
g−1
72% after 600 cycles at 2 A
g−1
This work
Mg0.34V2O5·nH2O 3M
Zn(CF3SO3)2
353, 330, 291, 264,
221, 167, and 81 mA
h g−1 at 0.05, 0.1,
0.5, 1, 2, 3, and 5 A
g−1, respectively
100% after 200 cycles at 0.1
A g−1
95% after 1000 cycles at 1 A
g−1
97% after 2000 cycles at 5 A
g−1
ACS
Energy
Letters
2018, 3,
2602
Na2V6O16·1.63H2O 3M
Zn(CF3SO3)2
352, 335, 316, 261,
219, and 162 mA h
g−1 at 0.05, 0.1, 0.2,
0.5, 1, and 2 A g−1,
respectively
78% after 100 cycles at 0.1 A
g−1
75% after 500 cycles at 1 A
g−1
90% after 6000 cycles at 5 A
g−1
Nano Lett.
2018, 18,
1758
Ca0.24V2O5·nH2O 1 M ZnSO4
~200, ~150, and 72
mA h g−1 at 10 C,
30C and 80C,
respectively
(1C=250 mA g−1)
96% after 3000 cycles at 80
C
78% after 5000 cycles at 80
C
Angew.
Chem. Int.
Ed. 2018,
57, 3943
Nano-Micro Letters
S9/S9
Zn3V2O7(OH)2·2H2O 1 M ZnSO4
200, 166, 145, 122,
105, 84, 75, and 54
mA h g−1 at 0.05,
0.1, 0.3, 0.5, 0.8, 1,
2, and 3 A g−1,
respectively
68% after 300 cycles at 0.2 A
g−1
Adv. Mater.
2018, 30,
1705580
Ag0.4V2O5 3 M ZnSO4 No accurate values
recorded in the text
216 mA h g−1 after 1000
cycles at 5 A g−1
155 mA h g−1 after 2000
cycles at 10 A g−1
Energy
Storage
Mater.
2018
Zn0.25V2O5·nH2O 1 M ZnSO4
~260, 223 and 183
mA h g−1 at 8C, 15
C, and 20 C,
respectively
(1C=300 mA g−1)
81% after 1000 cycles at 8 C
Nature
Energy
2016, 1,
16119
LiV3O8 1 M ZnSO4
(pH 4.0)
188, 148, 79, 47, and
29 mA h g−1 at
0.133, 0.266, 0.533,
1.066, and 1.666 A
g−1, respectively
90 % after 65 cycles at 0.133
A g−1
Chem.
Mater.
2017, 29,
1684
Table S2 Calculated Rct, σ and D values from the EIS results for the cathodes in five electrolytes
Electrolytes Rct(Ω) σ(Ω cm2 s-0.5) D(cm2 s-1)
2.0 M ZnSO4 275 145.24 2.68×10-15
1.5 M ZnSO4–0.5 M MgSO4 78 125.4 3.60×10-15
1.0 M ZnSO4–1.0 M MgSO4 106 68.425 1.21×10-14
0.5 M ZnSO4–1.5 M MgSO4 214 215.06 1.22×10-15
2.0 M MgSO4 334 343.55 4.79×10-16
Note: Rct represents the resistance of the charge during the transfer process in the electrode material from the
equivalent circuit.